Small Arrow Key Movement Code?

;Assumes (IX-2) and (IX-1) are 1 byte X and Y coordinates to modify
;Uses ti.GetCSC scan codes.
;Assumes that the keycode is 1,2,3, or 4, otherwise unexpected results.
;Destroys A,HL
    lea hl,ix-1
    sub a,2
    bit 1,a
    jr nz,$+1
    inc hl
    bit 0,a
    jr z,$+3
    inc (hl)
    jr $+1
    dec (hl)